1. Technical Field of the Invention
The present invention relates to a recording media cartridge such as a magnetic tape cassette or a digital video cassette (DVC), and more particularly to a recording media cartridge which facilitates attachment or detachment of a reel urging leaf spring for urging reels, i.e., a planar reel presser spring and which enables reduction of the impact on the environment.
2. Prior Art
Up to now, recording media cartridges used as video recording media for personal use or office use or as recording media used in external storage devices of computers or the like are categorized roughly into those using magnetic discs or magnetooptical discs as recording media (magnetic or magnetooptical disc cartridges or the like) and those using magnetic tape (magnetic tape cartridges).
Incidentally, as the latter magnetic tape cartridges, there are recording/reproducing tape cassettes used in video tape recorders or video cameras for personal use or office use and magnetic tape cassettes or magnetic tape cartridges used as large capacity recording media for data backup in external storage devices of computers or the like.
Also, as types of the magnetic tape cartridges, there are those formed by winding a magnetic tape around a single reel (so-called one-reel type magnetic tape cartridge) or those formed by winding a magnetic tape between two reels (so-called two-reel type magnetic tape cartridge or cassette). For instance, magnetic tape cassettes or the like with structures and dimensional specifications stipulated in JIS X6127, X6129, X6130, X6171, X6172 or ECMA-288 or the like are known.
The recording media cartridges such as these magnetic or magnetooptical disc cartridges or magnetic tape cartridges or magnetic tape cassettes are used for recording/reproducing or data storage in computers or the like, and precious images or sounds and/or important information are stored. Accordingly, these cartridges are structured so as to avoid damages to magnetic or magnetooptical discs, to avoid jamming of the magnetic tape, or to avoid the accidental drawing-out of the magnetic tape. For this reason, these various recording media cartridges are structured as composite structures obtained by combining various metal members and synthetic resin members according to the performance and shape required for each component for the structures.
A two-reel type magnetic tape cassette in which a magnetic recording tape wound around a pair of tape reels is held in a case body so as to be traveled for recording/reproducing will now be specifically described as an example of a recording media cartridge.
FIG. 33 is an exploded perspective view showing a structure of the above-described DVC as an example of this type magnetic tape cassette. As shown in FIG. 33, an upper half 20 and a lower half 22, each of which has a bottom plate and a peripheral wall, are assembled and fastened by screws 21 or the like and coupled in a face-to-face relationship to form a cassette case body (hereinafter simply referred to as a body case) 11 of this magnetic tape cassette 10. A pair of tape reels 24, 24 on a feeding side and a takeup side around which a magnetic tape 26 is wound are received between the upper half 20 and the lower half 22 of this body case 11.
Here, the tape reels 24, 24 are composed of a pair of reel hubs 24a, 24a around which the magnetic tape 26 is wound and upper flanges 24b, 24b and lower flanges 24c, 24c welded to upper and lower portions thereof and are received in the body case 11 to be rotatable.
Also, the tape reels 24, 24 are prevented from moving in their planar direction by a plurality of retaining ribs implanted in a bottom plate 22a of the lower half 22 so as to be in conformity with the outer circumferences thereof. Also, an opening is formed in the bottom plate of the upper half 20 so that the winding amount of the magnetic tape 26 around the tape reels 24, 24 can be confirmed. A transparent window (visible window) 20a is provided so as to cover this opening.
Also, a pair of metal-made reel urging leaf springs (hereinafter referred to as reel presser springs) 38, 38 are provided in an inner surface (a lower surface in the drawing) of the upper half 20, in correspondence with the respective tape reels 24, 24. The respective reel presser springs 38, 38 are fixed as in a cantilever on the inner surface of the upper half 20 and adapted to urge the corresponding tape reels 24, 24 toward the side of the lower half 22, respectively.
Here, the reel presser springs 38, 38 sufficiently urge the tape reels 24, 24 toward the lower half and also are firmly mounted directly or through a member onto the inner surface of the upper half by welding such as ultrasonic welding or thermal welding, caulking, adhesion or another method not so as to move away from a predetermined position during the use of the cassette or the like thus impeding the function and operation of other components or members in the cassette box. For example, as shown in FIG. 34, the reel presser spring 38 has been conventionally firmly fixed by passing a projection 20e provided on an inner surface 20b of the bottom surface of the upper half 20 through an anchor hole 38c formed in a support portion 38b curvedly followed by an elastic portion (urging end portion) 38a for urging the tape reel, and by deforming the projection 20e projecting from the anchor hole 38c by welding such as ultrasonic welding or thermal welding, caulking or another method thereby forming a wider welded portion 20f than the anchor hole 38c. 
A front cover (lid) 35 for covering and protecting a front surface and a back surface of the magnetic tape 26 to be tensioned between a pair of tape guides 46, 46 of the lower half 22 (described later) when this magnetic tape cassette 10 is not used is provided on the front surface (left side in the drawing) of the upper half 20 to obtain dust-proof property. As described later, this lid 35 is composed of three components, i.e., an outer lid 30, an upper lid 32 and an inner lid 34, which are mounted so as to freely open or close an opening portion 28 of the magnetic tape cassette 10, respectively.
The lower half 22 has a rectangular bottom plate 22a. The bottom plate 22a has reel shaft insertion holes 22b, 22b for rotatably supporting the pair of tape reels 24, 24 around which the magnetic tape 26 is wound and through which reel shafts (not shown) are inserted from a recording/reproducing device into the tape reels 24, 24 for their rotational driving when the magnetic tape cassette is loaded in the recording/reproducing device.
Also, the bottom plate 22a of the lower half 22 has a pair of projections 40, 40 extending forwardly from the left and right ends. The space between these projections 40, 40 is a space where the bottom plate 22a of the lower half 22 is not present to form the above-described opening portion 28 of the body case 11. Also, cylindrical tape guides 46, 46 for guiding the magnetic tape 26 tensioned between the pair of tape reels 24, 24 through a predetermined path to the front surface of the body case 11 are vertically implanted in the projections 40, 40 from the bottom plate 22a on both sides of the opening portion 28 of the front end side (front side in the drawing) of the lower half 22. That is, the respective tape guides 46, 46 are adapted to guide the magnetic tape 26 fed from one of the tape reels 24 and wound around the other of the tape reels 24 and cause the magnetic tape 26 to pass at a predetermined position of the opening portion 28.
Also, a tape reel lock member (hereinafter simply referred to as a reel lock member) 36 having tape reel anchor arms 36a and a slide drum portion 36b is assembled on the rear end side (on the deep side of the drawing) of the lower half 22. Here, the slide drum portion 36b is nipped slidably by means of a pair of guide ribs 43, 43 implanted in the bottom plate 22a of the lower half 22. This reel lock member 36 is urged by means of a metal-made compression coil spring (hereinafter referred to as a reel lock spring) 42 so that the tape reel anchor arms 36a are engaged with engagement teeth 24d, 24d formed on the outer circumferences of the lower flanges 24c, 24c of the respective tape reels 24, 24 to thereby prevent the accidental rotation of the respective tape reels 24, 24. Thus, the winding of the magnetic tape 26 is prevented from loosening.
Among the outer lid 30, the upper lid 32 and the inner lid 34 of the lid 35 mounted on the above-described upper half 20, lock pins 48 are provided to project on the inner side of the side plates of the outer lid 30 having the flat plate portion and the side plates. Then, lid lock members 44 for locking the lock pins 48 of the closed outer lid 30 are mounted rotatably on the side wall portions 22c that are parts of the circumferential wall of the lower half 22. The lid lock members 44 are urged toward a direction in which the above-described lock pins 48 are locked by means of lid lock springs 50 to be mounted on the lower half 22 in the same manner.
Also, an erroneous erasing preventing plug 52 for preventing the erroneous erasing of the data recorded onto the magnetic tape 26 is mounted on the lower half 22. The erroneous erasing preventing plug 52 has a claw portion projecting on one side surface (side surface on the deep side of the drawing) thereof. When the plug is mounted within the lower half 22, the claw portion is adapted to be exposed to the outside through an opening formed in the circumferential wall of the upper half 20.
Then, by operating this claw portion from the outside, it is possible to move the erroneous erasing preventing plug 52 along the guide rib implanted in the bottom plate 22a of the lower half 22. It is possible to close or open a detection hole provided in the bottom plate of the lower half 22 with the bottom surface of this erroneous erasing preventing plug 52. The equipment such as a recording device reads out the condition of this detection hole and determines whether new data may be input on the magnetic tape 26.
The above-described upper and lower halves 20, 22, outer lid 30, upper lid 32, inner lid 34, upper and lower flanges of the tape reels 24, 24 and the like are made of synthetic resin materials and are injection molded, respectively. Also, in addition to these, members injection molded are suitably used in the magnetic tape cassette.
On the other hand, the reel presser springs 38, 38, the reel lock spring 42 and the like are generally made of metal materials.
By the way, recently, as a concern in the environmental issue has been increased, the attention is paid increasingly to the effect on the environment due to the increase of various kinds of waste materials such as plastics and composite materials. It becomes important to reduce the impact on the environment, i.e., to reduce the waste materials, not to cause the air, water and soil pollution even if the materials are wasted, or not to cause the hindrance against the environmental protection. For this reason, also with respect to the industrial products, there is a demand for a structure that may be taken into the recycle use system.
For example, in the above-described magnetic tape cassette, it is general that the metal-made, planar reel presser spring that is seen through the transparent window provided in its body case is conventionally provided to the back surface of the upper half by welding such as ultrasonic welding or thermal welding, caulking, or by using adhesives (or screws) as described above. Also, the magnetic tape made from a material different from that of the body case is wound around the reels also made from a different material and received in the interior of the magnetic tape cassette.
The reel presser spring thus mounted performs its function sufficiently in the conventional magnetic tape cassette. In order to detach the reel presser spring upon dismounting of the magnetic tape cassette, however, it is difficult to detach the spring from the mounting portion. If the spring is to be forcibly detached, there arises a problem in that other parts such as an upper half would be damaged and parts could not be used in a recycle manner.
That is, as described above, according to the method of fixing the reel presser spring to the back surface of the upper half by welding, caulking, adhesion or the like, there is a problem in that, in order to remove the reel presser spring, a part (welded portion 20f in the example shown in FIG. 34) of the back surface of the upper half would be damaged and in this case, the broken pieces would be scattered to injury an operator or a part of the back surface of the resin forming the upper half is left on the reel presser spring side so that the desired sorting could not be performed. (Also, there is a problem in that it is time-consuming to remove the reel presser spring according to the method of fixing this reel presser spring to the back surface of the upper half by screws.)
Also, as described above, the reel lock member is received slidably within the interior of the magnetic tape cassette and the metal-made reel lock spring is received within the interior of the reel lock member. For this reason, in order to remove the metal-made reel lock spring, it is necessary to dismount the magnetic tape cassette, to remove the reel lock member from the magnetic tape cassette and to remove the spring from the removed resin made reel lock member. There is a problem in that it is troublesome to remove the spring.
Thus, it is difficult to perform the disassembly under the condition that the metal-made reel presser spring is not separated from the upper half but is fixed to the upper half as it is. Also, even if the used magnetic tape cassette may be disassembled, it is difficult to separate and sort the respective elements such as the metal-made reel presser spring, the reel lock spring, the resin made reel lock member, the magnetic tape, the upper and lower halves or the transparent window and to recycle these elements. For these reasons, there is a problem in that a large amount of waste synthetic resin materials are generated and the wasted synthetic resins cause the considerable impact on the environment. Also, not only in the case of the used materials but also in the case of the rejected products from the manufacturing process of the magnetic tape cassette, it is also difficult to recycle or disassemble the rejected products in the same manner. Also, it is effective to reduce the manufacturing cost of the magnetic tape cassette by recycling the parts made of expensive materials. However, in view of the above-described current situation, there is a problem in that it is also difficult to recycle the parts.
Accordingly, a primary object of the present invention is to provide a recording media cartridge having a novel structure which may simplify the disassembling work and which is advantageous when different materials are sorted in a case body (body case) of a recording media cartridge such as a magnetic tape cassette for eliminating the problems inherent in the above-described prior art, reducing the amount of waste materials and reducing the impact on the environment, more specifically, a structure that may dispense with welding, caulking or adhesion for fixing to an inner surface of an upper half a planar reel presser spring for urging reels around which a recording medium such as a magnetic tape is wound, and furthermore, a structure which can facilitate removal of a reel lock spring for preventing an accidental rotation of the reels and loosening of the magnetic medium wound.
More specifically, a first object of the present invention is to provide a recording media cartridge that may meet the following requirements:
i) to sufficiently perform the function that is required for the reel presser spring;
ii) to readily detach the reel presser spring from the upper half by one operation in a recyclable form without deformation upon the disassembling work of the magnetic media cartridge;
iii) to provide a superior assembling property when assembling, to readily perform the separation between synthetic resin and metal upon wasting, and even in case of wasting, to reduce the number of the wasted parts and not to cause the impact on the environment after disassembling; and
iv) to readily disassemble and collect the reel presser spring by one operation in a recyclable condition without damage or deformation and without damaging other structural parts such as a case body at the time when the magnetic media cartridge is to be disassembled in order to recycle the respective parts or members by disassembling the rejected products from the manufacturing process.
Also, more specifically, a second object of the present invention is to provide a recording media cartridge which may dispense with the conventional methods of fixing the reel presser spring to the upper half as exemplified by welding, caulking and adhesion, of which the spring can be assembled or disassembled with an efficiency as high as or higher than that in the conventional fixing methods even if a new anchor system is adopted, and of which the basic performance is not adversely affected by the change of the fixing method of the reel presser spring.
Also, more specifically, a third object of the present invention is to provide a recording media cartridge which, in the case where a structure is adopted where the reel presser spring may readily be assembled and removed, may assemble the spring with an efficiency as high as or higher than that in the conventional structure and of which the basic performance is not adversely affected by the change of the structure of the reel presser spring.
Also, more specifically, a fourth object of the present invention is to provide a recording media cartridge in which a reel presser spring may readily be removed to the outside without disassembling the case body and which is advantageous for separating and collecting the resin material and the metal material.
Also, more specifically, a fifth object of the present invention is to provide a recording media cartridge which, in the case where a structure is adopted where the reel lock spring may readily be removed, may assemble the spring with an efficiency as high as or higher than that in the conventional structure and of which the basic performance is adversely affected by the change of the structure of the reel presser spring.